411A inferior in what way?
The KC1 and K1 aircraft were modified to be tanker/freighter aircraft which was the requirement of the MOD at the time. Yes the K1 cargo system is poor, thats why they tend not to be used to many times in a freight role, put them up as a flying fuel station or on a trail then funny thing they do exactly what they were designed for.
The KC1, pretty damn capable in all the roles its needed to do.
The C2/C2a mods are required for the job we do, but essentially very little difference between them and the civvie version, The powers that be have decided that to do the job we do! we have to have that protection provided by those mods, this has not made it inferior? It has made it safer in the environment that we work in, why because the UK Govt do not want to take the risk, you might be happy to ask yr crews to do it, but we have a duty of care to the passengers down the back
So please stop talking utter tosh mate!